How to create an ArrayList of Classes?

Question

I have some classes (Car, Motorcycle, Train ... etc) that extends from class Vehicle. From another Class I need to create an ArrayList of Classes for access only to those that inlude the ArrayList.

The concept is similar to this, but obviously it doesn't work;

ArrayList<Class> vehicleType=new ArrayList<Class>();
vehicleType.add(Class.forName("train"));

How can I solve it ? Thanks

Answer 1

Most answers follow your suggestion of using Class.forName(), though that's not necessary. You can "call" .class on the type name.

Take a look at this JUnit test:

@Test
public void testListOfClasses() {

    List<Class<?>> classList = new ArrayList<Class<?>>();

    classList.add(Integer.class);
    classList.add(String.class);
    classList.add(Double.class);

    assertTrue("List contains Integer class", classList.contains(Integer.class));
}

I would expect for your need the list would be of type Class<? extends Vehicle>

Answer 2

If you're going to use the class loader (Class.forName), you need to use the fully qualified class name, i.e. Class.forName("com.package.Train");, exactly as you would reference it from the command line.